The present invention relates to a refrigerating apparatus which uses a Hydro Fluoro Carbon (hereinafter, referred to as HFC) group refrigerant, a refrigerating apparatus unit, an air-cooled type condenser unit and a compressor unit for a refrigerating apparatus, and, more particularly, the invention relates to a refrigerating apparatus which has an improved performance due to a stable operation and an increased refrigerating capacity.
A conventional refrigerating apparatus, for example, is described in Japanese Patent Unexamined Publication No. 8-159568, in the form of an air-cooled separate type refrigerating apparatus comprising a compressor unit and a separately provided air-cooled type condenser unit, and in which a liquid receiver is disposed within the air-cooled type condenser unit.
The conventional apparatus mentioned above is merely directed to a miniaturization of the compressor unit, provision of a sufficient of a service space and a prevention against lowering of the cooling performance of the liquid injection, but does not take into consideration the use of an HFC group pseudo-azeotropic mixture refrigerant, which has no influence on the earth""s ozone layer. Further, since a discharge port for the liquid injection is formed within the low pressure side device, there is a risk that the piping system will become complex in correspondence to the kind of low pressure side device to be connected thereto.
An object of the present invention is to provide a refrigerating apparatus using an HFC group refrigerant in which a condensed HFC group liquid refrigerant is prevented from becoming a flush gas midway of a pipe leading to an expansion valve from the condenser and which is able to achieve a stable operation and an increase in refrigerating capacity.
Another object of the invention is to provide a compact compressor unit and to reduce the space required therefor, in an air-cooled separate type refrigerator, which refrigerator is constituted by a compressor unit and an air-cooled type condenser unit.
A further object of the invention is to make it possible to make the degree of supercooling of the HFC group liquid refrigerant greater and to prevent a non-condensed gas from mixing into the liquid refrigerant introduced to a low pressure side device or to a liquid injection line.
A still further object of the invention is to make the piping system of the refrigerating apparatus simple.
In order to achieve the above objects, in accordance with a first aspect of the invention, there is provided a refrigerating apparatus having a pipe for circulating an HFC group pseudo-azeotropic mixture refrigerant or azeotropic mixture refrigerant in a closed manner using a compressor, a condenser for condensing the refrigerant discharged from the compressor, a liquid receiver to which the refrigerant from the condenser is supplied, a supercooler for further cooling the liquid refrigerant from the liquid receiver, an expansion valve for decompressing and expanding the refrigerant from the supercooler, and an evaporator for evaporating the refrigerant supplied from the expansion valve.
In accordance with a second aspect of the invention, there is provided a refrigerating apparatus having a pipe for circulating an HFC group refrigerant, such as an R404A and an R507A, in a closed manner using a scroll compressor, a condenser for condensing the HFC group refrigerant discharged from the scroll compressor, a liquid receiver to which the HFC group refrigerant from the condenser is supplied, a pipe for taking out only an HFC group liquid refrigerant having a dryness of 0 from the liquid receiver and feeding it to-a supercooler, an expansion valve for expanding the HFC group refrigerant from the supercooler, an evaporator for evaporating the HFC group refrigerant supplied from the expansion valve, an accumulator connected between the evaporator and the scroll compressor, and a liquid injection line for injecting liquid refrigerant passing between the condenser and the expansion valve to an intermediate pressure chamber in the scroll compressor.
Incidentally, in the structure mentioned above, it is also preferable to provide a crier for removing wafer mixed within the refrigerant and a sight glass capable of observing the flow state of the refrigerant in the refrigerant pipe extending between the supercooler and the expansion valve, and to provide the liquid injection line in such a manner as to inject the liquid refrigerant passing between the drier and the sight glass to the scroll compressor.
In accordance with a third aspect of the invention, there is provided a refrigerator having a compressor and a condenser, a refrigerant pipe for feeding an HFC group pseudo-azeotropic mixture refrigerant from the compressor to the condenser, a liquid receiver to which the refrigerant from the condenser is supplied, a supercooler for further cooling only the liquid refrigerant taken out from the liquid receiver, a refrigerant pipe for feeding the refrigerant from the supercooler to a low pressure side device, a liquid injection line for injecting a part of the liquid refrigerant in the refrigerant pipe to a compressing chamber in the compressor, and a refrigerant pipe for feeding the refrigerant from the low pressure side device to the compressor.
In accordance with a fourth aspect of the invention, there is provided a refrigerator having a scroll compressor and a condenser, a pipe for feeding an HFC group pseudo-azeotropic mixture refrigerant, such as R404A and an R507A, compressed by the scroll compressor, to the condenser, a liquid receiver to which the refrigerant from the condenser is supplied, a refrigerant pipe for taking out only liquid refrigerant having a dryness of 0 from the liquid receiver and feeding it to a supercooler, a refrigerant pipe for feeding the refrigerant from the supercooler to a low pressure side device, a drier provided in the refrigerant pipe for removing water mixed within the refrigerant and a sight glass capable of observing the state of flow of the refrigerant, a liquid injection fine for injecting the liquid refrigerant flowing between the drier and the sight glass to an intermediate compressing chamber of the scroll compressor, a refrigerant pipe for feeding refrigerant from the low pressure side device to the compressor via an accumulator.
In accordance with a fifth aspect of the invention, there is provided an air-cooled type condenser unit for a refrigerating apparatus having a condenser and a cooling fan, a refrigerant pipe for feeding an HFC group pseudo-azeotropic mixture refrigerant from the compressor unit to the condenser, a liquid receiver to which the refrigerant from the condenser is supplied, a supercooler for further cooling only liquid refrigerant taken out from the liquid receiver, and a refrigerant pipe for feeding the refrigerant from the supercooler to the compressor unit.
In accordance with a sixth aspect of the invention, there is provided a compressor unit for a refrigerating apparatus having a scroll compressor, a pipe for feeding an HFC group pseudo-azeotropic mixture refrigerant, such as an R404A and an R507A, compressed by the scroll compressor, to a condenser of an air-cooled type condenser unit for a refrigerating apparatus, a refrigerant pipe for supplying the refrigerant from the condenser unit to a low pressure side device, a drier provided in the refrigerant pipe for removing water mixed within the refrigerant, a liquid injection line for injecting the liquid refrigerant in the refrigerant pipe downstream of the drier to an intermediate compressing chamber of the scroll compressor, an electromagnetic valve and an electronic expansion valve which are disposed in the liquid injection line, a refrigerant pipe for feeding refrigerant from the low pressure side device to the scroll compressor via an accumulator.
In accordance with a seventh aspect of the invention, there is provided a compressor unit for a refrigerating apparatus having a scroll compressor, a pipe for feeding a refrigerant compressed by the scroll compressor to a condenser in an air-cooled type condenser unit for the refrigerating apparatus, a refrigerant pipe for supplying the refrigerant from the condenser unit to a low pressure side device, a vapor-liquid separator connected in the refrigerant pipe, a liquid injection line for injecting liquid refrigerant from a point downstream of the vapor-liquid separator to an intermediate compressing chamber of the scroll compressor, an electromagnetic valve and an electronic expansion valve which are disposed in the liquid injection line, a refrigerant pipe for feeding the refrigerant from the low pressure side device to the scroll compressor via an accumulator, the accumulator and the vapor-liquid separator being integrally constructed, and the refrigerant within the vapor-liquid separator being cooled by the refrigerant within the accumulator.
Incidentally, when the air-cooled type condenser unit for the refrigerating apparatus mentioned above is disposed outdoors and the compressor unit for the refrigerating apparatus mentioned above is disposed indoors and is connected by a pipe, an air-cooled separation type refrigerator can be obtained, and, further, when the low pressure side device having an expansion valve and an evaporator is connected thereto, the refrigerating apparatus can be constructed.
In accordance with an eighth aspect of the invention, there is provided a refrigerator having a scroll compressor and a condenser, a pipe for feeding an HFC group pseudo-azeotropic mixture refrigerant, such as an R404A and an R507A, compressed by the scroll compressor, to the condenser, a liquid receiver to which the refrigerant from the condenser is supplied, a refrigerant pipe for taking out only a liquid refrigerant having a dryness of 0 from the liquid receiver and feeding it to a supercooler, a refrigerant pipe for feeding the refrigerant from the supercooler to a low pressure side device, a vapor-liquid separator connected to the refrigerant pipe, a drier provided in the refrigerant pipe downstream of the vapor-liquid separator for absorbing and removing water mixed within the refrigerant, a sight glass provided in the refrigerant pipe disposed downstream of the drier for observing the state of the flow of refrigerant and any water contained within the refrigerant, a liquid injection line for injecting liquid refrigerant flowing between the drier and the sight glass to an intermediate compressing chamber in the scroll compressor, an electromagnetic valve and an electronic expansion valve which are provided in the liquid injection line, a refrigerant pipe for feeding refrigerant from the low pressure side device to the scroll compressor via an accumulator, the accumulator and the vapor-liquid separator being integrally constructed, and the refrigerant within the vapor-liquid separator being cooled by the refrigerant within the accumulator.
That is to say, in accordance with the respective characteristics mentioned above, since the HFC group pseudo-azeotropic mixture refrigerant, such as R404A and R507A, is used and the cycle system is constructed by connecting the compressor, the condenser, the liquid receiver and the supercooler in this order, the liquid refrigerant is sufficiently condensed, for example, and a liquid refrigerant having a dryness of 0 can be introduced to the supercooler, so that the heat transmission efficiency in the supercooler can be significantly improved.
Further, since the air-cooled condenser portion is disposed outdoors as an air-cooled type condenser unit, the compressor portion is disposed indoors as a compressor unit, to thereby construct the air-cooled separation type refrigerating apparatus, and since the liquid receiver is disposed within the air-cooled type condenser unit side, the three liquid pipes which are provided between the compressor unit and the air-cooled type condenser unit in the conventional system having the liquid receiver in the compressor unit side can be reduced to one liquid pipe in accordance with the invention. Further, since no liquid receiver exists within the compressor unit, the compressor unit can be made compact, so that the space required for disposing the compressor unit within the machine room, etc. can be greatly reduced.
Still further, since a compressor unit having an accumulator and an air-cooled condenser unit haying a liquid receiver (a first liquid receiver) temporarily storing the liquefied refrigerant are provided, the compressor unit and the air-cooled type condenser unit can be constructed as an air-cooled separation type refrigerating system in which the units are separated, the liquid receiver (a second liquid receiver) for separating the vapor from the liquid can be provided within the compressor unit, and the liquid receiver and the accumulator within the compressor unit can be integrally constructed while being separated by a partition plate, and the supercooling degree, of the liquid refrigerant can be made large.
Furthermore, in the apparatus in which the discharge port of the liquid injection line is disposed within the refrigerator or in the refrigerant pipe within the compressor unit, no matter what kind of low pressure side device is connected to the refrigerator, a complex pipe system is not required.
Other characteristics, objects and advantages of the invention will be clarified by the following description with reference to the attached drawings.